High efficiency polycrystalline phosphors and method of making same
US6254806A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 1999 |
| Grant date | Jul 3, 2001 |
| Priority date | — |
| Expiry date | May 14, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K11/7704
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A phosphor is provided that has a host material that is doped with a dopant having the chemical structure XCl.sub.3, where X is a rare earth element or combination of elements. A free oxygen contributor is also added to provide the free oxygen necessary to activate the rare earth dopant. The processing of the phosphor includes the heating of the phosphor in an over pressure environment of zinc, cadmium or tellurium. The heating is done in a two-temperature zone enclosed environment, so that impurities in the phosphor powder are condensed out on the cooler surface. Altematively, the dopant may be a material that does not include a rare earth element, such as copper, tellurium, cadmium, silver, potassium, manganese, magnesium, calcium, strontium, and barium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.